The present invention relates, in general, to probes of scanning probe microscopes and, in particular, to a method of making such probes.
Scanning probe microscopes, such as atomic force microscopes and scanning capacitance microscopes examine samples and provide information about the nature, characteristics, and structure of the samples that are being examined. An atomic force microscope, for example, provides information about the topography of a sample under investigation. A scanning capacitance microscope, for example, provides information about the electrical characteristics, such as the charge distribution, of the sample under investigation.
In scanning probe microscopes, a probe senses the property or feature of the sample that is of interest. For example, an atomic force microscope provides a high resolution view of the surface that is being imaged. The choice of material of the probe and the desired size and shape of the probe are dictated by the information that is of interest and the structure of the sample that is being investigated.
The level of information that can be developed about the nature, characteristics, and structure of a sample under investigation is limited by the size of the probe. For example, with atomic force microscopes, the resolution of the view of the surface being imaged is limited by how small the probe can be made.
There is an ongoing demand for higher and higher resolution probes. This means that there is a demand for smaller and smaller probes.
At the present time, lithography/etching techniques are the most widely used in fabricating the probes of scanning probe microscopes. Starting with the material of choice in bulk form, the desired shape of the probe is defined by lithography and formed by etching.
The lithography/etching techniques that are used to form the probes are reengineered for different probe designs and depend upon the choice of material of the probe and desired shape of the probe that is to be fabricated. The choice of probe material and design of probe shape, in turn, are dependent upon the particular application of the scanning probe microscope. Such reengineering of the lithography/etching technique adds cost to and delays in the fabrication of the probes.
Depending on the size and shape of the probe being fabricated, the lithography/etching process might be followed with ion milling to provide the finishing touches to the probe. Ion milling involves directing a high energy beam of ions to the probe to form the desired final shape of the probe. The additional step of ion milling adds to the cost and time required to fabricate the probe.
In addition, materials of choice for scanning probe microscope probes are not always readily available in bulk form. Consequently, other, less suitable, materials often are substituted in the fabrication of the probes or fabrication of the probes might be delayed undesirably.
It is an objective of the present invention to provide a new and improved method for fabricating a scanning probe microscope probe.
It is another objective of the present invention to provide a method by which a scanning probe microscope probe can be fabricated in a cost effective manner.
To achieve these and other objectives, a method for fabricating a scanning probe microscope probe in accordance with the present invention includes the steps of providing a mold having, in the body of the mold, a cavity in a shape and of a size of a desired form of a scanning probe microscope probe and lining the cavity with a release layer. A probe material is deposited in the cavity over the release layer to form a scanning probe microscope probe and the release layer is activated to release the scanning probe microscope probe from the cavity.